Antioxidant Activity of Pine Bark Constituents
AbstractA modified in vitro lipid peroxidation inhibition assay was used to guide the fractionation and the isolation of antioxidative principles of Finnish pine bark extract. This approach yielded 3,4-dihydroxybenzoic acid (protocatechuic acid) and taxifolin-3-O-β-glucopyranoside as major antioxidative compounds from the plant material. The structural elucidation of these compounds was undertaken with the help of HPLC-DAD and HPLC-ESI-MS analyses. Their IC50 values, in comparison to trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), were: trolox (1.78 ± 0.56 μm) < protocatechuic acid (5.77 ± 1.63 μm) < taxifolin-3- O-β-glucopyranoside (16.30 ± 1.98 μm). The method for the determination of antioxidant activity proved reproducible and quick for routine analyses with 96 well plates.